Integrated circuits have become more “dense” over time, i.e., more logic features have been implemented in an IC of a given size. Furthermore, signal swings have been reduced and frequencies of operation have increased. Accordingly, noise may play a more prominent role in causing problems in operation of an IC. Along those lines, debugging problems of a chip may involve a greater understanding of on-chip noise. Others have suggested using sub-sampling to measure on-chip noise, and while simple, sub-sampling is used for measuring periodic noise; however, not all noise is periodic noise. Others have suggested using autocorrelation to measure random noise; however, these approaches are complex and involve a substantial amount of routing overhead.
Accordingly, it would be desirable and useful to provide on-chip noise measurement capable of measuring random noise with less overhead than conventional autocorrelation on-chip noise measurement circuits.